And john h



(N0 Model.)

L. L. MAXFIELDXz-J. H. DARLINGTON. FIRE ALARM.

No. 505,987. Patented Oct. 3, 1-893.

WITNESSES: I NVENTGRS' ATTOHNEYJ. I

UNITED STATES PATENT OFFICE.

LEVERETT L. MAXFIELD, OF NEW YORK, AND JOHN H. DARLINGTON, OF

- BROOKLYN, NEW YORK.

FIRE-ALARM.

SPECIFICATION forming part of Letters Patent No. 505,987, dated October 3, 1893. Application filed February 27, 1892. Serial No.423,061. (No model.)

To all whom it may concern:

Be it known that we, LEVERETT L. MAX- The invention is shown as part of an alarm device adapted to be attached to doors and windows and to be operated on the opening thereof to sound an alarm.

In the accompanying drawings: Figure 1 is a view indicating one of our alarms applied to the frame of a door. Fig. 2 is a bottom view. Fig. 3 is a detail View showing the tripping arm and the catch devices that hold it in the normal position.

In the drawings A, A, are the front and back plates of an ordinary clock movement of which ais the scapementpallet and a the rockshaft carrying it. A detent lever B projects from this rock-shaft and is normally held in check by a small stud 0, carried on a spring or yielding plate 0 shown bolted to the front plate of the clock movement. The spring arm 0 tends normally to carry the lug out of the path of the detent arm and permits the vibration of the scapement, the rock-shaft of which carries a hammer X operating upon a gong or bell Y. A second flat plate or arm D is arranged alongside of the arm 0. The arm D is stiffer than the arm O, which latter is held up so as to project the lug 0 into the path of the detent lever by means of the plug d, which may be of some suitable plastic fusible or semi-fusible material interposed between the two arms. In the event of fire the increasing temperature will cause the softening or melt ing of this plug, and the arm 0 falls away from the detent lever removing the lug from out of the path of the lever and permitting the sounding of the bell. Electrical contacts 6, f, may be mounted respectively on the arms 0, D, so that upon the softening or melting of the fusible plug d the contacts will come together and complete an electric circuit, terminals of which are indicated by the broken wires e',f', and sound a suitable alarm at a distant point. A third spring arm G bolted to the other side plate of the clock train is bent as shown and as hereinafter described is adapted to bear uponthe spring arm 0. Its end is turned as shown at gand is formed with a catch g"that engages the edge of the side plate. The spring arm G has a greater spring pressure or power than the arms O, D, and whenreleased or tripped as presently described, it presses against the arm 0 and forces the lug 0 out of the path of the detent arm, thus causing the alarm to sound. After the arm G has been tripped it may be restored to the normal position by means of a push rod H passing through the rods D, O, and connected with the rod G. The end 9 of the rod G projects laterally from the catch g and has hinged thereto a tripping arm I. The arm I may be held out in a lateral position by a spring catch 2', and then projects across or beyond the edge of the door, as shown in Fig. 1. When the door is opened therefore, it presses against the arm, releases the catch g and the arm G throws the spring 0 down, carrying the lug 0 out of the path of the detent arm releasing the clock train which sounds the alarm. During the daytime, or when the alarm is not needed, the catchol may be released and the arm I then falls by gravity and hangs out of the path of the door as indicated in Fig. 3.

Instead of the fusible plug d, the spring arm 0 may be held up by a fusible band .9, as of india rubber, shown in Fig. 2 in dotted lines, as passing around the arm 0 and the bent end of arm G. y

We claim as our invention 1. The combination of a clock train, its escapement, its gong or bell, a hammer therefor, an arm projecting from the escapement, a controlling lever, adapted to dog said arm, and fusible material, normally holding the controlling lever in such position as to cause the dogging of the arm, andconsequently of the clock train, but adapted upon an abnormal rise in temperature to release the lever,

to liberate said arm and permit the sounding of an alarm, substantially as set forth.

2. The combination with a clock train, its gong or bell and a hammer of a controlling lever, adapted in one position to dog the clock train, and an elastic band engaging said lever and drawing it into said position thereby normally causing the dogging of the clock train, the elastic band being adapted, upon an abnormal increase of temperature, to melt or soften and release the lever and permit the sounding of an alarm, substantially as set to forth.

In testimony whereof we have hereunto subscribed our names.

LEVERETT L. MAXFIELD. JOHN H. DARLINGTON. Witnesses:

GEO. W. GILBERT, P. L. BOUGHER. 

